Stable preparations of vat dyestuffs and process for making same



Patented Ma 17, 1932 UNITED STATES;

PATENT OFF-[ca mu rniirz uannncrmnarm mam ntnummcn, ornocnsr-on-m-m1mem m, assmnoas r ennmn minim wonxs, me, or new CORPORATION or DELAWARE STABLE rnnrmi rons or var nYEs'rurrs am) raocnss roa Mame no Drawing. Application filed October 1, 1926, Serial 1%. 139,012, and 1.. Germany October 17,198.-

Our presentinvention relates to the' roduction of stable preparations of vatyestufis.

Vat-dyestuffs to be used for dyein wool,

5 are mostly put on the market in the ibrm of the alkali metal-salts of their leuco compounds, for instance in the form of a liquid or solid vat, whereby the dyer is enabled to carry out the dyeing process without having to use an alkali, which fact is of the utmost importance because, when wrong doses of the alkali lye are used the wool-fibre will be injured. There have been produced also solid preparations of vat dyestufls by mix- 1 in the dyestuffs with an alkali and hydro su fite and adding then a dispersing agent. Now we have found that preparations of vat dyestuffs of very good stability, containing the requisite quantity of alkali and yield- 2 ing with water on additionof a reducing agent vats. ready for use are obtainedby adding-to the .dry dyestufi-powders, instead of an alkali, the equivalent'quantity of a dry pulverized alkali starch-preparation. Thereby the addition of a special dispersing-agent is rendered unnecessary.- The said alkali starch-preparations are'particularly suitable for the above mentioned purpose because, unlike pulverized caustic alkali, they are very little hygroscopic and are.o'nly slowly and to a small extent decomposed. by the carbonic acid contained inthe air. Similar results may be obtained by using a mixture of caustic alkali and starch insteadof the readymade alkali starch-preparations. In this case the moisture absorbed 'b the caustic alkali from the surrounding air is rendered innocuous by the formation of the compound of caustic alkali and starch which takes place immediately wherever moisture arises.

By these preparations there areofi'ered to the dyer vat dyestuffs combined with just 'the quantity of alkali required for the vatting; in order to-obtain the desired vats the dyer has only to mix the dyestufi-powder with a 'wetting or dispersing a ent and water and to add the required quantlty of 'hydrosulfite.

The hydrosulfiteand the wetting or dispersing agents, for instance a salt of a sulfonic acid of unsaturated fatty acid, ligninstance with so-called monopol soap sulfonates or a substance of similar action,

. the above described dyes'tufi-pow er prepa- YORK, N. Y A.

rations without impairing their stability. It

is advantageous to add the wetting ordispersing agents when drying paste. which contain already all in edients required for the vatting, are readily soluble in moderately heated water and eminently stable. and, when dissolved in water, they yield vats which are any further addition.

The alkali starch-preparation to be used according to the following examples may be made as follows:

ready for use without 4 the dyestufi The preparations ust described,

3 parts by weight of starcli are mixed and I stirred at ordinary temperature with 4.5

parts by weight of caustic soda solution of 40 B.; at first there is obtained a colloidal solution which, after about 15- minutes,

solidifies into a white powdered mass. This powder is dried ina vacuumat 80" and ground to a fine dust. A titrometrl'c test shows that the powder contains 39% of NaOH. The composition of the alkali starches may largely vary; it is, however,

advantageous to employ such preparations as contain one molecule of starch to 1.5-5 molecules of caustic soda.

Examples 1) 50 parts by weight of di-J(p-'chloranilido) -benzoquinone in the form of a dry powder are intimately mixed with 95 parts by weight of the dry, ground alkali-starch of the composition indicated above.the preparation thus obtained gives a clear vat by a for incovering it with a wetting agent,

(sodium sulforicinolate) and warm water and adding 60. arts,by wei'ght of hydrosulfite.

(2) n indigo-paste, containing 50 parts by weight of indigo, is evaporated to dryness with a solution of 2.5 parts of sodium 11 nsulfonate. The resulting mass is mixe and 1 ground with 69 parts of the alkalistarch and 80 parts by weight of hydrosulfite. .The

preparation thus obtained on being covered w1th warmwatcryields a vat ready for use.

2 rmm' (3) To 150 parts by weight of 30% paste of the brown vatdye'stufi obtainable by the proeem described in S. Patent No. 1,128,368 of Februa 16, 1915, are added 12 v 5 parts by weight of one 1 soap, whereuponthe paste is'evapora todryness. The 3 dry mass is intimately mixed and ground with 80 arts by we ht of alkali starch and 70 parts y weight 0 hydrosulfite. On covering the preparation. thus obtained with warm water, a vat is obtained which is quite i di 'ra b ht r as d' pa y we1g o om igored powder, containing of 'monopol soapare mixed and und with 96 parts b weight of the alkai starch preparation. 0 dyestufl preparation thus obtained gives a clear vat on covering it with warm water. andadding 80 parts by weight of hydrosul- (5) 150 parts b wei ht of a paste of the brown vat yestu obtainable by the process described in U. S. Patent No. 1,128,368 are evaporated to dryness with 10 v .parts by weight of :mono l soap and the resultin mass is then mix and ground with 50 arts y weight of dry starch, 33 parts by weight of caustic soda and '70 parts by weight of h'ydrosulfite. On addition of warm wa- 30 ter, the preparation thus obtained yields a vat whic is quite ready for use.

f The quantity of soillauused in the orego ex'amp e ma w 0 or part y replace d by another al izali, for iiistance' sodium carbonate.

Allthe preparations made by the process set forth in the foregoing exam les have proved to remain unaltered even w en being ex to the air for several months.

the following claims we understand by the term alkali not 0111 the caustic alkalis, but also the car nates o the alkalis.

weclaimz 1. As new products, stable vat dy'estufi preparations compri a vat dyestufi, al-

. kali starch and by fite.

'2. As new products, stable vat dyestufi mparations comprising a vatdyestufi, al-

starch, hydrosulfite and a wettin agent.

33. :As new products, stable vat yestufi I mparations of a vat dyestufi, al-

starch, by te'and monopol soap. cny whereof, we afiixour S g a- KARL FRITZ MAENNCHEN.

amnion. 

